but you wording suggest that you seem to think it is only being practised by the UK side of the negotiations.

Where in the UK might St Petersberg be?

they was deliberately vague but there is no doubt it refers to the politically oriented even if there is no nationality stated or (& I can be the authority on that point) ............ implied.
It has been inferred though. And other than my words, I am not in control of that.

There is no doubt that Europe has something to lose by not securing a deal. But the UK has more to lose. So playing my "life ain't binary" card, I am of the opinion that the brinkmanship is more irresponsible when the loss is the greater.

Change costs money, and this change will cost, and payback is ill-defined. Making deals at the last minute means dependent systems/infrastructure will be formulated in a hurry, and mistakes will be made. Which is why change costs more money. Which is why the UK has more to lose.